I can't find any documentation supporting piping stdout to mutt, but it works for me. Provide the
-nc to gcal for plain text output. Use
--cal to specify a calendar to use. The agenda argument tells gcalcli to list the next three days' events.
gcalcli --nc --cal home agenda| mutt -s "subject here" -c phonenumber1@smsgateway phonenumber2@smsgateway
I run this in my crontab and everbody in the family gets a text message listing upcoming events.
This works especially well for me. I drop phones a lot and just get dumbphone replacements.